The subway train LED display design method

The subway on the LED screen is divided into two kinds of

a place in the carriage of the lateral, displays the current train operation interval, running direction and arrive station stops, compatible display in both Chinese and English; Also can according to the operation need to display other information services; Text display optional stationary, rolling, translation, waterfalls, animation and so on the many kinds of effects, the biggest display number is 16 * 16 dot matrix characters of 12 characters. End of another kind of LED display, placed in the car, the terminal LED display can be preset terminus, according to the requirements of train operation and real-time display the current terminal, but also can display the temperature inside the car, the biggest display characters of 16 * 16 lattice eight characters.

the LED screen display system consists of two parts, single-chip microcomputer control unit and display unit

single display unit 16 x 16 four Chinese characters can be shown, if produced in the production of a certain size LED graphic display system, with a number of intelligent display unit, adopt the method of 'building blocks' can be realized, the system adopts serial communication link between the display unit. Control unit in addition to control display unit and upper machine instruction and signal transmission, and embedded the single bus digital temperature sensor 18 b20. Thanks to the control circuit module design, if also has asked for humidity measurement, 18 b20 can be upgraded to Dallas company DS2438 and HoneywELl HIH23610 constitute module circuit. In order to meet the requirements of vehicle communication, the PC with the car's way of using CAN bus communication between control units.

display unit consists of two parts, LED display panel and display circuit

the LED display panel is made up of four dot matrix module 16 * 64 lattice general intelligent display unit, a single display unit full screen can display four 16 * 16 dot matrix characters or symbols, and display unit of the system adopts serial communication link between, so as to make the work of the whole system harmonious and unified. Display circuit made up of two 16 needles platoon line, two 74 h245 tristate bus driver, a 74 hc04d six inverter, two 74 h138 eight decoder and 8 74 hc595 are needed shift of latch. Core control circuit for high speed single chip microcomputer 77 e58 WINBOND, crystal frequency to 24 MHz. A ROM T29C020A is 256 K, used for storage of 16 * 16 dot matrix of Chinese character and 16 x 8 dot matrix of ASCII code. A T24C020 is based on the I2 C serial bus EP2ROM, its storing this set of statements, such as the subway site name, greeting and so on. Temperature inside the car through single bus digital temperature sensor 18 b20 measurement. SJA1000 and TJA1040 respectively CAN bus controller and transceiver.

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the LED screen mesh